Cathodic protection anode assembly



Jan. 30, 1962 FIC-Inl E. P. ANDERSON CATHODIC PROTECTION ANODE ASSEMBLY Filed Jan. 8, 1959 INVENTOR.

EDWARD P. ANDERSON Kaal #um .7M E, Bv w ATTORNEYS United States Patent O 3,019,177 CATHODIC PROTECTION ANODE ASSEMBLY Edward P. Anderson, Livingston, NJ., assiguor, by mesue assignments, to Engelhard Industries, Inc., Newark, NJ., a corporation of Delaware Filed Jau. 8, 1959, Ser. No. 785,680

5 Claims. (Cl. 204-196) This invention relates to anode assemblies for cathodic protection systems.

The cathodic protection of submerged painted surfaces, such as a ships hull, involves the use of one or more anodes which are insulated from the hull, Iand the application of direct current between the anode or anodes and the hull as a cathode. By this means, the usual rust and corrosion by electrochemical action is avoided. Many large naval vessels have been equipped with cathodic protection systems, and it has recently been proposed to extend this protection to smaller boats of the pleasure craft type. In this regard, however, the high cost of the systems which have been available up to the present time has prevented the`- use of cathodic-protection systems in this small boat,iield. A `suitableinexpensive power supply for this field isudisclosed in my copending patent application Serial No. 766,147, tiled October 8, 1958.

' In addition tothe problem of developing less expensive power supplies for cathodic protection systems, the anode assembliesemplpyed Qn larger vessels are quite expensive. The ,high cost ofanodes, employed in larger vessels results principally from the expensive materials which are employed. Thus, for example, platinum clad titanium or tantalum Ianodes are preferred for this purpose. In view of the high current densities required for adequate coverage in large vessels, the anode structures were necessarily large and required considerable amounts of costly platinum metal.

Accordingly, the principal object of the present invention is the reduction in cost of anode assemblies.

In accordance with the present invention, an anode assembly is made up of platinum coated wire, bent back and forth to form a series of generally parallel wire segments. The ends of the wire segments are turned inwardly and are embedded in a plastic insulating support member. The parallel segments of wire rest on one surface of the insulating support. At a desired point, the wires forming the parallel grid have their ends turned inwardly through the plastic support member to a point within the hull of the ship on which the anode is to be secured. A metallic supporting ferrule or sleeve is flared outwardly, and has its ared edges embedded in the plastic support. 'I'he ferrule also extends from the plastic support on the side away from the grid of anode wires. This protruding end of the ferrule is threaded so that the ferrule may be passed through a hole in the hull of the ship and rigidly secured in position. The ends of the platinum coated wire extend through the plastic support and the supporting ferrule into the hull. The anode wire is, of course, insulated from the hull. A cathodic protection power supply may then be connected between the anode leads and the hull.

In accordance with a feature of the invention, an anode assembly for cathodic protection purposes includes a series of parallel wire segments having their ends embedded in a plastic support. The parallel wire segments are electrically connected to lead-in wires passing through the plastic supporting member.

Other objects, features and various advantages of the present invention will become apparent from a consideration of the following detailed description and the accompanying drawings, in which;

FIGURE 1 is a plan view of an anode in accordance with the present invention; and

3,019,177 Patented Jan. 30, 1962 FIGURE 2 is a cross sectional view along lines II-II of FIGURE l, showing associated components and eircuitry.

With reference to FIGURE l, the anode assembly includes a streamlined insulating support 12, which may, for example, be made of a fiberglass-reinforced polyester resin. The metallic anode per se is made up of the series of wire segments 14. In a preferred form of the inven tion, the Wire segments 14 include only two separate pieces of platinum coated wire. Both of the two pieces of Wire are connected together at the terminal 16 as shown in FIGURE 2. The other end of the two pieces of wire are shown at 18 and 20 in FIGURE 1. At the points where the wires are bent back upon themselves, they are also bent inwardly. One such bend is shown at 22 in FIGURES l and 2. The entire anode assembly, made up of the Wire segments 14, is secured in place by the use of plastic material as shown at 24 and 26 in FIG- URE 2, which holds the inwardly bent portions of the wires 14 rigidly against the support 12.

In the fabrication of the anode assembly, the fiberglass-reinforced resin plates 12 are initially formed. Thereafter, six holes are drilled at each end of the plastic plate. In addition, a central opening of stepped dimensions is provided for the flared ferrule 28. Following the assembly of the ferrule 28 and the wire segments 14 with the plate 12, the additional plastic material mentioned above is poured into the openings and forms the final rigidassembly as shown in FIGURES 1 and 2.

With reference to FIGURE 2, the anode assemblyis secured in place to the hull 30 by an assembly including a rubber washer 32, a steel washer 34, and a nut 36 which is threaded on the protruding end of the ferrule 28. An insulating blanket 38 may be mounted between the iiberglass-reinforced insulating support 12 and the hull 30. The insulating blanket may extend for a desired distance around the anode assembly to preclude paint damage which might otherwise result from high current densities on the hull surface near the support 12. Suitable cement and caulking compound may be employed in securing the anode assembly to the hull. In addition, a junction box may be employed within the hull to protect the Wires, as disclosed A. l. Zwanzig patent application Serial No. 742,213, led June 16, 1958. A cathodie protection power supply 40, such as that disclosed in my copending application Serial No. 766,147, mentioned above, may be connected between the terminal 16 and the hull 30.

In FIGURE l the arrow 42 indicates the longitudinal axis of the boat to which the anode is secured. Thus, in FIGURE 2 the longitudinal axis of the boat is perpendicular to the plane of the drawing. With this arrangement, the wires 14 produce little turbulence to the ow of water. In addition, the possibility of fouling is minimized.

The anode assembly, as described above, has the advantages of utilizing very little expensive platinum metal. In addition, the exposed cylindrical surfaces of the platinum coated wires 14 provide a high current density relative to the amount of platinum which is included in the anode assembly. An extremely economical anode assembly is therefore provided which still has sufficient current capacity to adequately protect the surface of small craft.

It is to be-understood that the above described arrangements are illustrative of the application of the principles of the invention. Numerous other arrangements may be devised by those skilled inthe art without departing from the spirit and scope of the invention.

What is claimed is:

1. In an anode assembly for the cathodic protection of small craft, a generally flat, streamlined, :fiberglass-reinforced, insulating support; a metallic tube having a anged end embedded in said support and a threaded end extending from one side of said support for securing the anode assembly to the hull of said craft; and a Wire serving as the anode and having one end extend ing through and insulated from said tube, the remainder of said wire Ibeing bent to form la plurality of generally straight parallel wire segments spaced from each other and forming an exposed grid on the other surface of said support, the portions of said Wire which interconnect the ends of said segments being bent out of the plane of said grid and being embedded in said support.

2. An `anode assembly comprising a platinum coated wire serving as the anode and being bent back and forth to forrn an essentially at grid of substantially straight parallel wire segments spaced from each other, the bent portions of the wire being turned away from the plane of the grid of parallel wire segments, and a plastic insulating support member having a surface in contact with said wire segments and having the bent portions cmbedded in it.

'3. An anode assembly for oathodic protection purposes comprising a plastic supporting member, a threaded ferrule having one end embedded in said support on one side of said support, and a platinum coated wire serving as the anode and being bent back and forth to lform a plurality of wire segments spaced from each other and located on the other surface of said support, the portions of said Wire which interconnect the ends of said segments being embedded in said support.

4. An anode assembly comprising 'a conducting wire serving asl the' anode and being bent back and forth to form a grid of substantially parallel Wire segments spaced from each other, the bent portions of the wire being turned to extend away from the plane of the grid of parallel wire segments, a plastic insulating support member having a surface in -contact with said Wire segments and having the bent portions embedded in one side of said support member, and a ferrule extending from the other side of said support and having a flanged end embedded in said support.

5. In combination, a hull of a boat having a predeten mined longitudinal axis, a generally at, streamlined, fiberglass-reinforced, insulating support, mounted on said hull, a metallic tube having a flanged end embedded in said support and the other end extending through said hull; and a wire serving as the anode and having one end extending through and insulated from said tube, said wire being bent to form a plurality ofy generally straight parallel segments spaced from each other and forming an exposed grid on the other surface of said support, said segments being oriented parallel with said axis, the portions of said wire which interconnect the ends of said segmentsl being bent out of the plane of said grid and being embedded in said support.

References Cited inthe lle of this patent UNITED STATES PATENTS 

1. IN AN ANODE ASSEMBLY FOR THE CATHODIC PROTECTION OF SMALL CRAFT, A GENERALLY FLAT, STREAMLINED, FIBERGLASS-REINFORCED, INSULATING SUPPORT; A METALLIC TUBE HAVING A FLANGED END EMBEDDED IN SAID SUPPORT AND A THREADED END EXTENDING FROM ONE SIDE OF SAID SUPPORT FOR SECURING THE ANODE ASSEMBLY TO THE HULL OF SAID CRAFT; AND A WIRE SERVING AS THE ANODE AND HAVING ONE END EXTENDING THROUGH AND INSULATED FROM SAID TUBE, THE REMAINDER OF SAID WIRE BEING BENT TO FORM A PLURALITY OF GENERALLY STRAIGHT PARALLEL WIRE SEGMENTS SPACED FROM EACH OTHER AND FORMING AN EXPOSED GRID ON THE OTHER SURFACE OF SAID SUPPORT, THE PORTIONS OF SAID WIRE WHICH INTERCONNECT THE ENDS OF SAID SEGMENTS BEING BENT OUT OF THE PLANE OF SAID GRID AND BEING EMBEDDED IN SAID SUPPORT. 